﻿#define _CRT_SECURE_NO_WARNINGS 1
class Solution
{
public:
	bool isInterleave(string s1, string s2, string s3)
	{
		// 1. 创建 dp 表 
		// 2. 初始化 
		// 3. 填表 
		// 4. 返回值 
		int m = s1.size(), n = s2.size();
		if (m + n != s3.size()) return false;
		s1 = " " + s1, s2 = " " + s2, s3 = " " + s3;
		vector<vector<bool>> dp(m + 1, vector<bool>(n + 1));
		dp[0][0] = true;
		for (int j = 1; j <= n; j++) // 初始化第⼀⾏ 
			if (s2[j] == s3[j]) dp[0][j] = true;
			else break;
		for (int i = 1; i <= m; i++) // 初始化第⼀列 
			if (s1[i] == s3[i]) dp[i][0] = true;
			else break;
		for (int i = 1; i <= m; i++)
			for (int j = 1; j <= n; j++)
				dp[i][j] = (s1[i] == s3[i + j] && dp[i - 1][j])
				|| (s2[j] == s3[i + j] && dp[i][j - 1]);
		return dp[m][n];
	}
};
